Mycotoxicology and Chemoprevention Research Group, Institute of Biomedical and Microbial Biotechnology, Cape Peninsula University of Technology, PO Box 1906, Bellville 7535, South Africa.
Oxidative Stress Research Centre, Institute of Biomedical and Microbial Biotechnology, Cape Peninsula University of Technology, PO Box 1906, Bellville 7535, South Africa.
Int J Food Microbiol. 2019 May 2;296:31-36. doi: 10.1016/j.ijfoodmicro.2019.02.016. Epub 2019 Feb 20.
Maize (Zea mays), sorghum (Sorghum bicolor) and pearl millet (Pennisetum glaucum) are basic staple foods for many rural or poorer communities. These crops are susceptible to plant diseases caused by multiple species of Fusarium, some of which also produce mycotoxins, including fumonisins and moniliformin that are detrimental to both humans and domesticated animals. Eighteen potentially toxigenic Fusarium strains were isolated from maize (n = 10), sorghum (n = 7) and pearl millet (n = 1) growing in the same field in Nigeria. The 17 strains from maize and sorghum were all F. proliferatum and the one strain from pearl millet was F. pseudonygamai. Under conducive conditions, the 17 F. proliferatum strains produced fumonisins, 11 in relatively large quantities (700-17,000 mg total fumonisins, i.e., FB + FB + FB/kg culture material), and six at <45 mg/kg. Ten F. proliferatum strains produced >100 mg of moniliformin per kg culture material with a maximum of 8900 mg/kg culture material. All strains could use all grains for growth and toxin production, regardless of the host from which they were isolated. Isolates varied in the amount of toxin produced on each substrate, with toxin production a property of the strain and not the host from which the strain was recovered. However, the extent to which a toxin-producing phenotype could be altered by the grain on which the fungus was grown is consistent with subtle genetic × environment interactions that require a larger data set than the one presented here to rigorously identify. In conclusion, there is significant variation in the ability of strains of F. proliferatum to produce fumonisins and moniliformin on maize, sorghum and millet. If the amount of toxin produced on the various grains in this study reflects real-world settings, e.g., poor storage, then the consumers of these contaminated grains could be exposed to mycotoxin levels that greatly exceed the tolerable daily intakes.
玉米（Zea mays）、高粱（Sorghum bicolor）和珍珠粟（Pennisetum glaucum）是许多农村或较贫困社区的基本主食。这些作物容易受到多种镰刀菌物种引起的植物病害的影响，其中一些物种还会产生霉菌毒素，包括伏马菌素和单端孢霉烯族毒素，这对人类和家养动物都有害。从尼日利亚同一田间种植的玉米（n=10）、高粱（n=7）和珍珠粟（n=1）中分离出了 18 株潜在产毒镰刀菌菌株。来自玉米和高粱的 17 株菌均为层出镰刀菌，来自珍珠粟的一株菌为拟轮枝镰刀菌。在适宜条件下，17 株层出镰刀菌菌株产生了伏马菌素，其中 11 株菌产生的伏马菌素含量较高（700-17,000mg 总伏马菌素，即 FB+FB+FB/kg 培养物），6 株菌的含量低于 45mg/kg。10 株层出镰刀菌菌株每公斤培养物产生的单端孢霉烯族毒素超过 100mg，最高为 8900mg/kg 培养物。所有菌株均可利用所有谷物进行生长和毒素产生，而与它们分离自哪个宿主无关。分离株在每种基质上产生毒素的量不同，毒素产生是菌株的特性，而不是菌株回收的宿主的特性。然而，产毒表型在多大程度上可以通过真菌生长的谷物来改变，这与微妙的遗传×环境相互作用一致，需要比这里提出的更大的数据集来严格识别。总之，层出镰刀菌菌株在玉米、高粱和小米上产生伏马菌素和单端孢霉烯族毒素的能力存在显著差异。如果本研究中各种谷物上产生的毒素量反映了真实环境，例如储存条件差，那么这些受污染谷物的消费者可能会接触到大大超过可耐受日摄入量的霉菌毒素水平。
